Abstract. Three debris-flow gullies, the Hong-Shui-Xian (HSX), Sha-Xin-Kai (SXK), and Xin-Kai-Dafo (XKD) gullies, located in the Shinfa area of southern Taiwan, were selected as case studies on the discharge of landslide-induced debris flows caused by Typhoon Morakot in 2009. The inundation characteristics of the three debris flows, such as the debris-flow volume V , deposition area A d , and maximum flow depth, were collected by field investigations and simulated using the numerical modeling software FLO-2D. The discharge coefficient c b , defined as the ratio of the debrisflow discharge Q dp to the water-flow discharge Q wp , was proposed to determine Q dp , and Q wp was estimated by a rational equation. Then, c b was calibrated by a comparison between the field investigation and the numerical simulation of the inundation characteristics of debris flows. Our results showed that the values of c b range from 6 to 18, and their values are affected by the landslide ratio R L . Empirical relationships for c b versus R L , Q dp versus Q wp , Q dp versus V , and A d versus V are also presented.
Typhoon Morakot struck central and southern Taiwan on August 8, 2009, and the high rainfall intensity and accumulated rainfall-induced several floods, landslides, and debris flows. In this study, the destructive debris flow caused by Typhoon Morakot in the Sha-Xinkai gully of the Liouguei District in southern Taiwan was selected as a case study for analysis. A two-dimensional model (FLO-2D software) was used to simulate debris flow. First, hydrological and geomorphological data were collected on the debris flow event and the rheological properties of slurry collected from the field were analyzed. Next, the relationship between debris flow discharge and water flow discharge was obtained. The simulation results for the deposited area and depth were then compared to aerial photos taken during a field investigation. Finally, the bulked coefficient of discharge and the resistant parameters used in the model were presented. The results showed that the maximum deposited depth in the debris flow inundated area was over 6 m; the maximum velocity, 6.6 m/s; and the deposited volume, almost 1,000,000 m 3. The simulated deposition depth and inundation area matched the results from the field investigation reasonably well. In this study, the parameters and processes needed for the simulation of landslide-induced debris flows were proposed to provide a reference for hazard zone mapping and debris flow hazard mitigation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.